Lessons Learned from My Failed Greenland Prediction and NOAA’s Shifting Goalposts

Watts Up With That?

Guest Thread by Jim Steele

In December 2014, I posted the essay Will Greenland Begin Accumulating Ice in 2015 and Beyond. Based on 1) my understanding of Greenland’s icecap dynamics, 2) changes in the North Atlantic Oscillation and its effect on heat transport, and 3) NOAA’s 2014 Arctic Report Card indicating a rapid deceleration in loss of ice mass (an insignificant 6 gigatons Gt), I argued that Greenland could begin accumulating ice starting as early 2015. Ice mass loss can only happen if summer melt exceeds annual accumulation, or if greater basal melting of glaciers and iceberg calving increases glacier discharge and offsets accumulation. However the inflow of warm Atlantic water has been declining, and suggested basal melting and glacier discharge should be decreasing. Furthermore as the high pressure system that governs Greenland’s weather shifted, snow accumulation was once again exceeding summer melt, suggesting a reversion to the mean…

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